Carbosilicon.



UNITED STATES PATENT OFFICE.

, HENRY NOEL POTTER, OF NEW ROCHELLE, NEW YORK, A SSIGNOR TO GEORGEWESTINGHOUSE, F PITTSBURGH, PENNSYLVANIA.

' Patented June 25, 1912.

CARBOSIIJIGON.

1 30,132 7 Specification of Letters latent.

No Drawing.

Application filed March 22, 1904. Serial No. 199,507.

heated silicon unite to form atough, closegrained, hard, non-porousmaterial of high specific electrical resistance and great inertness tooxidation at high temperatures. The material possesses other valuableproperties and I have given it the name of carbosilicon. The materialthus named is valuable for many purposes, notably as a heatingresistance for electrical apparatus. It is also adapted to be used as anelectrode for vacuum or vapor tubes for lighting or other purposes, as1t appears to contain little or no occluded gas.

Carbosilicon does not resemble a chemical compound of definiteproportion but is more like an alloy having properties different fromits constituents but shading gradually at each extreme into the one or te other. It is not a mere mixture, as the two constituents lose theirphysical individualit As an analogy, it may be said that the addition ofsilicon carbid to silicon affects the latter somewhat as the addition ofiron carbid (Fe c cementite) affects iron, making it bettermechanically.

Carbosilicon may be produced b melting silicon in contact with siliconcar id. The latter may be given the shape of the completed article bpressing owdered silicon carbid and bin er in amo d. It may then bebrought into contact with molten silicon, whereupon silicon will beabsorbed and the new material produced. It may also be produced bytreating a mixture of silicon carbid and silica in an electric furnace.A

mixture of one hundred (100) parts silicon carbid to fifty parts silicawill react and produce it. When the proportion of silica is too lOW theprdduct does not flow readily and forms a sponge in the furnace insteadof a compact mass.

A mixture of silicon carbid and silicon in the form of dry (powders canbe pressed into shape and bake into this new material,

but such masses tend to chip apart in a pcculiar and characteristic way,which would seem to indicate a powerful force seekmgto aggreate theconstituents in some manner so di erent from a heterogeneous mixture,

as, in its formation to rupture the mass Carbosilicon can be. attachedby caustic alkalies and by a mixture of-nitric and bydrofluoric acids.insoluble silicon carbid remains. serves asaquick method of analysis todetermine the proportion of silicon carbid.

Both silicon and silicon carbid, as at present produced, contain smallquantities of impurities, for example, I have found traces of aluminum,calcium. and iron present, but not in-such quantities as to materiallyafiect the product. B silicon carbid, I mean either the amorp ous orcrystalline modification, the latter being known as carborundum.

I claim as my invention The process of producing 'carbo-silicon whichconsists inressing powdered silicon carbid and a bin mg material into acompact form and then bringing it into contact with molten silicon.

Signed at New York, in the county of New York, and State of New York,this 14th day of March, A. D. 1904.

v HENRY NOEL POTTER.

Witnesses:

WM. H. CAPEL, GEORGE H. STOOKBRIDGE.

The silicon dissolves and This

